A randomized clinical trial of the efficacy and safety of rivipansel for sickle cell vaso-occlusive crisis.

The efficacy and safety of rivipansel, a predominantly E-selectin antagonist, were studied in a phase 3, randomized, controlled trial for vaso-occlusive crisis (VOC) requiring hospitalization (RESET). A total of 345 subjects (204 adults and 141 children) were randomized and 320 were treated (162 with rivipansel, 158 with placebo) with an IV loading dose, followed by up to 14 additional 12-hourly maintenance doses of rivipansel or placebo, in addition to standard care. Rivipansel was similarly administered during subsequent VOCs in the Open-label Extension (OLE) study. In the full analysis population, the median time to readiness for discharge (TTRFD), the primary end point, was not different between rivipansel and placebo (-5.7 hours, P = .79; hazard ratio, 0.97), nor were differences seen in secondary end points of time to discharge (TTD), time to discontinuation of IV opioids (TTDIVO), and cumulative IV opioid use. Mean soluble E-selectin decreased 61% from baseline after the loading dose in the rivipansel group, while remaining unchanged in the placebo group. In a post hoc analysis, early rivipansel treatment within 26.4 hours of VOC pain onset (earliest quartile of time from VOC onset to treatment) reduced median TTRFD by 56.3 hours, reduced median TTD by 41.5 hours, and reduced median TTDIVO by 50.5 hours, compared with placebo (all P < .05). A similar subgroup analysis comparing OLE early-treatment with early-treatment RESET placebo showed a reduction in TTD of 23.1 hours (P = .062) and in TTDIVO of 30.1 hours (P = .087). Timing of rivipansel administration after pain onset may be critical to achieving accelerated resolution of acute VOC. Trial Registration: Clinicaltrials.gov, NCT02187003 (RESET), NCT02433158 (OLE).

Impact of arginine therapy on mitochondrial function in children with sickle cell disease during vaso-occlusive pain.

Altered mitochondrial function occurs in sickle cell disease (SCD), due in part to low nitric oxide (NO) bioavailability. Arginine, the substrate for NO production, becomes acutely deficient in SCD patients with vaso-occlusive pain episodes (VOE). To determine if arginine improves mitochondrial function, 12 children with SCD-VOE (13.6 ± 3 years; 67% male; 75% hemoglobin-SS) were randomized to 1 of 3 arginine doses: (1) 100 mg/kg IV 3 times/day (TID); (2) loading dose (200 mg/kg) then 100 mg/kg TID; or (3) loading dose (200 mg/kg) followed by continuous infusion (300 mg/kg per day) until discharge. Platelet-rich plasma mitochondrial activity, protein expression, and protein-carbonyls were measured from emergency department (ED) presentation vs discharge. All VOE subjects at ED presentation had significantly decreased complex-V activity compared to a steady-state cohort. Notably, complex-V activity was increased at discharge in subjects from all 3 arginine-dosing schemes; greatest increase occurred with a loading dose (P < .001). Although complex-IV and citrate synthase activities were similar in VOE platelets vs steady state, enzyme activities were significantly increased in VOE subjects after arginine-loading dose treatment. Arginine also decreased protein-carbonyl levels across all treatment doses (P < .01), suggesting a decrease in oxidative stress. Arginine therapy increases mitochondrial activity and reduces oxidative stress in children with SCD/VOE. This trial was registered at www.clinicaltrials.gov as #NCT02536170.

PROMIS(®) pediatric self-report scales distinguish subgroups of children within and across six common pediatric chronic health conditions.

PURPOSE: To conduct a comparative analysis of eight pediatric self-report scales for ages 8-17 years from the National Institutes of Health (NIH) Patient Reported Outcomes Measurement Information System (PROMIS(®)) in six pediatric chronic health conditions, using indicators of disease severity. METHODS: Pediatric patients (N = 1454) with asthma, cancer, chronic kidney disease, obesity, rheumatic disease, and sickle cell disease completed items from the PROMIS pediatric mobility, upper extremity functioning, depressive symptoms, anxiety, anger, peer relationships, pain interference, and fatigue self-report scales. Comparisons within the six pediatric chronic health conditions were conducted by examining differences in groups based on the disease severity using markers of severity that were specific to characteristics of each disease. A comparison was also made across diseases between children who had been recently hospitalized and those who had not. RESULTS: In general, there were differences in self-reported health outcomes within each chronic health condition, with patients who had higher disease severity showing worse outcomes. Across health conditions, when children with recent hospitalizations were compared with those who had not been hospitalized in the past 6 months, we found significant differences in the expected directions for all PROMIS domains, except anger. CONCLUSIONS: PROMIS measures discriminate between different clinically meaningful subgroups within several chronic illnesses. Further research is needed to determine the responsiveness of the PROMIS pediatric scales to change over time.

Red blood cell alloimmunization in sickle cell disease: prevalence in 2010.

BACKGROUND: Transfusion of red blood cells (RBCs) is frequently required for care of individuals with sickle cell disease (SCD). Alloimmunization rates are high and may be reduced by matching for RBC antigens that can cause alloimmunization. STUDY DESIGN AND METHODS: During the PROACTIVE Feasibility Study, patients with SCD age 2 years or older admitted for pain without acute chest syndrome were enrolled for possible randomization to preventive blood transfusion or standard care. Transfusion and antibody histories were obtained at each site, and antibody screening was done, to assess transfusion burden and alloimmunization prevalence. Participating sites were surveyed regarding antigen matching practice. RESULTS: A total of 237 patients (169 SS, 42 SC, 15 Sß(0) -thalassemia, 11 Sß(+) -thalassemia), 118 males and 119 females, were enrolled. Mean age was 19.3 years (range, 2.0-68.0); there were 122 children and 115 adults. A total of 75.8% had received at least a single transfusion of RBCs before the study. Thirty-four patients (14.4%) had a history of at least one alloantibody and 17 of these had more than one. When surveyed, 19 sites (83% of responders) reported antigen matching to at least include C, E, and K for transfusion of all patients with SCD. CONCLUSION: Though antigen typing before transfusion of people with SCD and providing antigen-negative units is now widely employed by sickle cell centers, the alloimmunization rate remains quite high in contemporary sickle cell populations and may be due in large part to transfusions received at institutions not providing extended matching.

IMPROVE trial: a randomized controlled trial of patient-controlled analgesia for sickle cell painful episodes: rationale, design challenges, initial experience, and recommendations for future studies.

BACKGROUND: The hallmark of sickle cell disease (SCD) is pain from a vaso-occlusive crisis. Although ambulatory pain accounts for most days in pain, pain is also the most common cause of hospitalization and is typically treated with parenteral opioids. The evidence base is lacking for most analgesic practice in SCD, particularly for the optimal opioid dosing for patient-controlled analgesia (PCA), in part because of the challenges of the trial design and conduct for this rare disease. PURPOSE: The purpose of this report is to describe our Network's experiences with protocol development, implementation, and analysis, including overall study design, the value of pain assessments rather than 'crisis' resolution as trial endpoints, and alternative statistical analysis strategies. METHODS: The Improving Pain Management and Outcomes with Various Strategies (IMPROVE) PCA trial was a multisite inpatient randomized controlled trial comparing two PCA-dosing strategies in adults and children with SCD and acute pain conducted by the SCD Clinical Research Network. The specified primary endpoint was a 25-mm change in a daily average pain intensity using a Visual Analogue Scale, and a number of related pain intensity and pain interference measures were selected as secondary efficacy outcomes. A time-to-event analysis strategy was planned for the primary endpoint. RESULTS: Of 1116 individuals admitted for pain at 31 participating sites over a 6-month period, 38 were randomized and 4 withdrawn. The trial was closed early due to poor accrual, reflecting a substantial number of challenges encountered during trial implementation. LIMITATIONS: While some of the design issues were unique to SCD or analgesic studies, many of the trial implementation challenges reflected the increasing complexity of conducting clinical trials in the inpatient setting with multiple care providers and evolving electronic medical record systems, particularly in the context of large urban academic medical centers. LESSONS LEARNED: Complicated clinical organization of many sites likely slowed study initiation. More extensive involvement of research staff and site principal investigator in the clinical care operations improved site performance. During the subsequent data analysis, alternative statistical approaches were considered, the results of which should inform future efficacy assessments and increase future trial recruitment success by allowing substantial reductions in target sample size. CONCLUSIONS: A complex randomized analgesic trial was initiated within a multisite disease network seeking to provide an evidence base for clinical care. A number of design considerations were shown to be feasible in this setting, and several pain intensity and pain interference measures were shown to be sensitive to time- and treatment-related improvements. While the premature closure and small sample size precluded definitive conclusions regarding treatment efficacy, this trial furnishes a template for design and implementation considerations that should improve future SCD analgesic trials.

Tissue factor-positive monocytes in children with sickle cell disease: correlation with biomarkers of haemolysis.

Tissue Factor (TF) initiates thrombin generation, and whole blood TF (WBTF) is elevated in sickle cell disease (SCD). We sought to identify the presence of TF-positive monocytes in SCD and their relationship with the other coagulation markers including WBTF, microparticle-associated TF, thrombin-antithrombin (TAT) complexes and D-dimer. Whether major SCD-related pathobiological processes, including haemolysis, inflammation and endothelial activation, contribute to the coagulation abnormalities was also studied. The cohort comprised children with SCD (18 HbSS, 12 HbSC, mean age 3·6 years). We demonstrated elevated levels of TF-positive monocytes in HbSS, which correlated with WBTF, TAT and D-dimer (P = 0·02 to P = 0·0003). While TF-positive monocytes, WBTF, TAT and D-dimer correlated with several biomarkers of haemolysis, inflammation and endothelial activation in univariate analyses, in multiple regression models the haemolytic markers (reticulocytes and lactate dehydrogenase) contributed exclusively to the association with all four coagulant markers evaluated. The demonstration that haemolysis is the predominant operative pathology in the associated perturbations of coagulation in HbSS at a young age provides additional evidence for the early use of therapeutic agents, such as hydroxycarbamide to reduce the haemolytic component of this disease.

Inpatient management of sickle cell pain: a 'snapshot' of current practice.

The Sickle Cell Disease Clinical Research Network (SCDCRN) designed the PROACTIVE Feasibility Study (ClinicalTrials.gov NCT00951808) to determine whether elevated serum levels of secretory phospholipase A2 (sPLA2) during hospitalization for pain would permit preemptive therapy of sickle cell acute chest syndrome (ACS) by blood transfusion. While PROACTIVE was not designed to assess pain management and was terminated early due to inadequate patient accrual, collection of clinical data allowed a "snapshot" of current care by expert providers. Nearly half the patients admitted for pain were taking hydroxyurea; hydroxyurea did not affect length of stay. Providers commonly administered parenteral opioid analgesia, usually morphine or hydromorphone, to adults and children, generally by patient-controlled analgesia (PCA). Adult providers were more likely to prescribe hydromorphone and did so at substantially higher morphine equivalent doses than were given to adults receiving morphine; the latter received doses similar to children who received either medication. All subjects treated with PCA received higher daily doses of opioids than those treated by time-contingent dosing. Physicians often restricted intravenous fluids to less than a maintenance rate and underutilized incentive spirometry, which reduces ACS in patients hospitalized for pain.

Opioid patient controlled analgesia use during the initial experience with the IMPROVE PCA trial: a phase III analgesic trial for hospitalized sickle cell patients with painful episodes.

Opioid analgesics administered by patient-controlled analgesia (PCA)are frequently used for pain relief in children and adults with sickle cell disease (SCD) hospitalized for persistent vaso-occlusive pain, but optimum opioid dosing is not known. To better define PCA dosing recommendations,a multi-center phase III clinical trial was conducted comparing two alternative opioid PCA dosing strategies (HDLI­higher demand dose with low constant infusion or LDHI­lower demand dose and higher constant infusion) in 38 subjects who completed randomization prior to trial closure. Total opioid utilization (morphine equivalents,mg/kg) in 22 adults was 11.6 ± 2.6 and 4.7 ± 0.9 in the HDLI andin the LDHI arms, respectively, and in 12 children it was 3.7 ± 1.0 and 5.8 ± 2.2, respectively. Opioid-related symptoms were mild and similar in both PCA arms (mean daily opioid symptom intensity score: HDLI0.9 ± 0.1, LDHI 0.9 ± 0.2). The slow enrollment and early study termination limited conclusions regarding superiority of either treatment regimen. This study adds to our understanding of opioid PCA usage in SCD. Future clinical trial protocol designs for opioid PCA may need to consider potential differences between adults and children in PCA usage.

Comparing abstract numerical and visual depictions of risk in survey of parental assessment of risk in sickle cell hydroxyurea treatment.

Communicating risk is an important activity in medical decision-making; yet, numeracy is not a universal skill among the American public. We examined the hypothesis that numerical risk information about the use of hydroxyurea for children with sickle cell disease would elicit different risk assessment responses when visual depictions were used instead of abstract numbers and depending on the disease severity. Parents of 81 children with sickle cell disease participated in a survey in which hydroxyurea was first described as carrying a certain chance of risk for both birth defects and cancer. Then, the parents indicated the highest risk at which they would hypothetically consent to the treatment to help their child. Risk presentations were repeated with abstract numerical, pie graph, and 1000 people histogram formats. The χ analyses comparing high-risk to low-risk assessment across presentation formats showed high consistency between visual depictions but low consistency of abstract numerical with visual depictions. The parents of children with SC and other less severe types of SCD were less willing to accept higher risk than those with SS when the data were presented numerically. Given earlier concerns about poor "numeracy" in the US population, visual depictions of risk could be an effective tool for routine communication in health education and medical decision-making.

Definitions of the phenotypic manifestations of sickle cell disease.

Sickle cell disease (SCD) is a pleiotropic genetic disorder of hemoglobin that has profound multiorgan effects. The low prevalence of SCD ( approximately 100,000/US) has limited progress in clinical, basic, and translational research. Lack of a large, readily accessible population for clinical studies has contributed to the absence of standard definitions and diagnostic criteria for the numerous complications of SCD and inadequate understanding of SCD pathophysiology. In 2005, the Comprehensive Sickle Cell Centers initiated a project to establish consensus definitions of the most frequently occurring complications. A group of clinicians and scientists with extensive expertise in research and treatment of SCD gathered to identify and categorize the most common complications. From this group, a formal writing team was formed that further reviewed the literature, sought specialist input, and produced definitions in a standard format. This article provides an overview of the process and describes 12 body system categories and the most prevalent or severe complications within these categories. A detailed Appendix provides standardized definitions for all complications identified within each system. This report proposes use of these definitions for studies of SCD complications, so future studies can be comparably robust and treatment efficacy measured. Use of these definitions will support greater accuracy in genotype-phenotype studies, thereby achieving a better understanding of SCD pathophysiology. This should nevertheless be viewed as a dynamic rather than final document; phenotype descriptions should be reevaluated and revised periodically to provide the most current standard definitions as etiologic factors are better understood, and new diagnostic options are developed.

iCanCope with Sickle Cell Pain: Design of a randomized controlled trial of a smartphone and web-based pain self-management program for youth with sickle cell disease.

Many adolescents with sickle cell disease (SCD) experience recurrent and chronic pain, which has a negative impact on their health-related quality of life (HRQL). Cognitive-behavioral therapy (CBT) interventions can lead to improvement in pain and HRQL, yet due to barriers to care, most youth with SCD will not receive these interventions. To address this need for innovative programs targeting youth with SCD pain, we developed iCanCope, a tailored smartphone and web-based program that delivers a pain self-management intervention to youth with SCD. We describe the rationale, design, and implementation of a three-site parallel group randomized controlled trial with a sample of 160 adolescents with SCD and their parent caregivers. The iCanCope program includes pain self-management skills training (personalized CBT-based coping skills such as deep breathing, relaxation, and cognitive skills), goal setting, and social support. The attention control group is provided with access to a self-guided website with education about SCD. Assessments will occur at baseline (T1), immediately after completion of the intervention (12 weeks; T2) and at 6 months post-intervention (T3). Primary outcomes include coping strategies and pain intensity; secondary outcomes include physical, social, and emotional functioning, treatment satisfaction, health service use and caregiver response to youth pain behavior. Potential mediators (goal setting, self-management, and perceptions of social support) and moderators (e.g., demographic factors) will also be tested. The objective is to offer an effective, convenient, and low-cost psychosocial intervention to youth with SCD to enhance their self-management of pain.

Double-blind, randomized, multicenter phase 2 study of SC411 in children with sickle cell disease (SCOT trial).

Blood cell membranes in sickle cell disease (SCD) have low docosahexaenoic acid (DHA). DHA treatment reduces sickle cell crisis (SCC) rate and ameliorates the inflammation, oxidative stress, and hypercoagulable state of SCD. SC411 is a novel DHA ethyl ester formulation with a proprietary delivery platform (Advanced Lipid Technology) that enhances DHA bioavailability. The SCOT trial investigated the effect of 3 different doses of SC411 on clinical and biochemical endpoints in 67 children with SCD (5-17 years old). Seventy-six percent of subjects were also receiving hydroxyurea. After 4 weeks of treatment with SC411 at 20, 36, and 60 mg DHA/kg per day or placebo a statistically significant (P < .001) mean percentage increase of blood cell membrane DHA and eicosapentaenoic acid was seen vs baseline: 109.0% (confidence interval [CI], 46.7-171.3), 163.8% (CI, 108.3-219.2), 170.8% (CI, 90.2-251.4), and 28.6% (CI, 250.1 to 107.3), respectively. After 8 weeks of treatment, statistically significant changes vs placebo were also observed in D-dimer (P = .025) and soluble E-selectin (P = .0219) in subjects exposed to 36 mg/kg. A significant increase in hemoglobin was observed against placebo in subjects receiving 20 mg DHA/kg per day (P = .039). SC411 significantly reduced electronic diary recorded SCC, analgesic use at home, and days absent from school because of sickle cell pain. The lower rate of clinical SCC observed in the pooled active groups vs placebo did not reach statistical significance (rate ratio, 0.47; 95% CI, 0.20-1.11; P = .07). All tested doses were safe and well tolerated. This trial was registered at www.clinicaltrials.gov as #NCT02973360.

Clinical trial designs and models for analgesic medications for acute pain in neonates, infants, toddlers, children, and adolescents: ACTTION recommendations.

Clinical trials to test the safety and efficacy of analgesics across all pediatric age cohorts are needed to avoid inappropriate extrapolation of adult data to children. However, the selection of acute pain models and trial design attributes to maximize assay sensitivity, by pediatric age cohort, remains problematic. Acute pain models used for drug treatment trials in adults are not directly applicable to the pediatric age cohorts-neonates, infants, toddlers, children, and adolescents. Developmental maturation of metabolic enzymes in infants and children must be taken into consideration when designing trials to test analgesic treatments for acute pain. Assessment tools based on the levels of cognitive maturation and behavioral repertoire must be selected as outcome measures. Models and designs of clinical trials of analgesic medications used in the treatment of acute pain in neonates, infants, toddlers, children, and adolescents were reviewed and discussed at an Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) Pediatric Pain Research Consortium consensus meeting. Based on extensive reviews and continuing discussions, the authors recommend a number of acute pain clinical trial models and design attributes that have the potential to improve the study of analgesic medications in pediatric populations. Recommendations are also provided regarding additional research needed to support the use of other acute pain models across pediatric age cohorts.

Clinical trial implementation and recruitment: lessons learned from the early closure of a randomized clinical trial.

BACKGROUND: The NHLBI-sponsored Sickle Cell Disease Clinical Research Network (SCDCRN) conducted a multi-center, acute intervention randomized clinical trial of two methods of Patient Controlled Analgesia for acute pain. This trial was terminated early due to low enrollment. We analyzed the perceived barriers and recruitment difficulties as reported by the coordinators and principal investigators. METHODS: Participating sites completed a missed eligibility log of subjects admitted in pain crisis throughout the study and a survey at the end of the trial. The survey covered site-specific factors, policies, and procedures in study implementation, recruitment strategies, and eligibility factors. The New England Research Institutes (NERI) collected de-identified surveys from 31 respondents at 29 of 31 participating sites. RESULTS: From December 2009 to June 2010, 1116 patient encounters for SCD and pain occurred at participating institutions: 38 subjects were enrolled (14 pediatric and 24 adults) and 34 completed the trial, below the projected 278 subjects. Fourteen sites enrolled subjects and seventeen did not. Recruitment barriers included insufficient staff, subject ineligibility or in too much pain to consent, competing protocols, and concerns regarding pain control. Recruitment methods were referrals from urgent care, SCD clinics and in house databases. No use of media or outside physicians was reported. CONCLUSION: We identified multiple barriers to patient accrual including short duration of enrollment period, protocol design, complex dosing schedule, requirement for staff availability during week-end and after hours, multiple departments' involvement, protocol acceptance, eligibility criteria, competing protocols, and limited staff. Each of these areas should be targeted for intervention in order to plan and conduct successful future clinical trials.

Pediatric analgesic clinical trial designs, measures, and extrapolation: report of an FDA scientific workshop.

Analgesic trials pose unique scientific, ethical, and practical challenges in pediatrics. Participants in a scientific workshop sponsored by the US Food and Drug Administration developed consensus on aspects of pediatric analgesic clinical trial design. The standard parallel-placebo analgesic trial design commonly used for adults has ethical and practical difficulties in pediatrics, due to the likelihood of subjects experiencing pain for extended periods of time. Immediate-rescue designs using opioid-sparing, rather than pain scores, as a primary outcome measure have been successfully used in pediatric analgesic efficacy trials. These designs maintain some of the scientific benefits of blinding, with some ethical and practical advantages over traditional designs. Preferred outcome measures were recommended for each age group. Acute pain trials are feasible for children undergoing surgery. Pharmacodynamic responses to opioids, local anesthetics, acetaminophen, and nonsteroidal antiinflammatory drugs appear substantially mature by age 2 years. There is currently no clear evidence for analgesic efficacy of acetaminophen or nonsteroidal antiinflammatory drugs in neonates or infants younger than 3 months of age. Small sample designs, including cross-over trials and N of 1 trials, for particular pediatric chronic pain conditions and for studies of pain and irritability in pediatric palliative care should be considered. Pediatric analgesic trials can be improved by using innovative study designs and outcome measures specific for children. Multicenter consortia will help to facilitate adequately powered pediatric analgesic trials.